The World Health Report 2000, prepared by the World Health Organization, presented performance rankings of 191 nations' health care systems. These rankings have been widely cited in public debates about health care, particularly by those interested in reforming the U.S. health care system to resemble more closely those of other countries. Michael Moore, for instance, famously stated in his film SiCKO that the United States placed only 37th in the WHO report. CNN.com, in verifying Moore's claim, noted that France and Canada both placed in the top 10.

Those who cite the WHO rankings typically present them as an objective measure of the relative performance of national health care systems. They are not. The WHO rankings depend crucially on a number of underlying assumptions -- some of them logically incoherent, some characterized by substantial uncertainty, and some rooted in ideological beliefs and values that not everyone shares.

The analysts behind the WHO rankings express the hope that their framework "will lay the basis for a shift from ideological discourse on health policy to a more empirical one." Yet the WHO rankings themselves have a strong ideological component. They include factors that are arguably unrelated to actual health performance, some of which could even improve in response to worse health performance. Even setting those concerns aside, the rankings are still highly sensitive to both measurement error and assumptions about the relative importance of the components. And finally, the WHO rankings reflect implicit value judgments and lifestyle preferences that differ among individuals and across countries.